How to Clean a Katana

Since functional samurai swords are made of high-carbon steel, they can rust if not properly cared for. Learning how to clean a katana is one of the easiest and most important things you can do. Just by following some easy steps, you will ensure that your blade stays shiny and safe in its scabbard, ready for the next battles.

In this article, I’m going to show you how to clean and oil a katana at home, covering everything you need to know about its maintenance.

First-Time Cleaning

When you receive your brand new katana, you might want to touch the blade to feel its sharpness or even perform some cutting tests. Once you finish, it’s important to clean and oil the blade. Most new swords come oiled from the factory. The first cleaning process is recommended right after you receive it(if you don’t plan on doing cutting tests right away).

Remove the old factory oil and apply a fresh one. If you plan to test your katana, there’s no need to oil it beforehand. Simply wait until you’re done testing, then clean and apply.

How Often Should I Clean my Katana

If you haven’t used your sword, cleaning it every 5 to 6 months is sufficient. The most important thing is to clean it right after each use, regardless of what you’re cutting, whether it’s tatami, bamboo, liquid bottles or anything else.

If stored in a humid place, make sure to check it regularly and clean it more often.

Things You Should Avoid When Cleaning

Touching the Blade with Bare Hands

The natural oils from your skin can lead to corrosion. Always avoid direct contact with the blade, and use gloves or handle it by the handle only.

Over-Oiling

Over oiling can oxidize the blade or even deteriorate the scabbard from the inside.

How to Clean a Katana- Step by Step

If your Japanese sword came with a maintenance kit, follow the steps in this guide for cleaning. If you don’t have one, you can easily order a katana maintenance kit online and, after you get it, get back to following the steps.

If you’re unsure how to use a katana cleaning kit, don’t worry. It’s simple. You can start by understanding each item and its purpose. The cleaning kit will include:

Choji Oil – A clove-based oil. You’ll apply this as a final layer to keep the katana polished and shielded.

Uchiko Ball – A small cotton ball filled with fine polishing powder. This helps lift off old oil and debris, prepping the blade for a fresh clean.

Cleaning Cloths – Several cloths are included for different stages (nuguigami). One for wiping away residue, one for polishing, and another for applying the oil.

Brass Hammer – Used to carefully tap out the bamboo pegs, allowing you to disassemble the handle if deeper cleaning is needed.

1. Get Everything Ready

Before beginning the cleaning process, ensure you have all the necessary tools at hand. Take your katana and open the cleaning kit.

2. Disassemble the Katana (Optional)

This step is optional and isn’t necessary. However, if it’s been a long time since the last disassembly, it’s a good idea to check for rust.

If you want a thorough cleaning, disassemble the katana by carefully removing the mekugi. Use a mekugi-nuki (peg removal tool) to gently tap the peg out of the tsuka (handle).

Once it’s removed, gently slide the blade out of the handle.

3. Clean the Blade

Grab the nuguigami from the kit (or a clean, soft cloth). Carefully wipe down the blade to remove any old oil, dust, or residue. Start from the base and work your way towards the tip, using a gentle, consistent motion.

4. Apply the Uchiko Powder

Next, take the uchiko ball and lightly tap it along the length of the blade (both sides).

5. Remove the Powder

Use another fresh piece of nuguigami (or clean cloth) to wipe off the powder. Make sure to use smooth, even strokes so the blade ends up completely clean and free of any particles.

5. Apply Oil

Apply a small amount of choji oil directly onto the blade or onto the cloth you’re using. Spread the oil evenly along the entire length of the blade, from the base to the tip, using gentle, consistent strokes.

6. Reassemble the Katana (If Disassembled)

Place the habaki (collar) onto the blade, followed by the seppa (washers) and tsuba (guard). Then, carefully slide the handle (tsuka) back onto the blade, aligning it with the peg hole. Insert the mekugi and tap gently if needed to secure it firmly.

7. Sheath your Sword

Once cleaned and oiled, check one last time to make sure that there is no dry spots on the blade. Place the katana back in its saya (scabbard). Always do this gently to prevent any nicks or scratches to the blade.

Display the katana horizontally with the edge facing up to reduce pressure on the edge and prevent dulling.

Cleaning a Katana Without a Kit: Using Household Items

If you don’t have a proper katana maintenance kit, don’t worry, you can still clean it using common household items. While these aren’t perfect substitutes for traditional tools, they can work effectively to keep your blade in good shape.

Start by gathering a few simple items: a soft, lint-free cloth, some rubbing alcohol, and mineral oil or baby oil. The rubbing alcohol will help to remove any old oil, dirt, or fingerprints on the blade. Just dampen a cloth slightly with alcohol and gently wipe down the blade, being careful to avoid the sharp edge. Make sure the blade is completely dry afterward.

Next, use another clean cloth to apply a very light coating of mineral or baby oil to the blade. Make sure not to use too much oil.

Using household items for katana maintenance isn’t ideal for the long term, but it’s a practical way to care for your sword when a proper kit isn’t available.

Last Words

By following these maintenance steps, you’ve already learned how to care for a katana, helping it stay in great condition for years to come. Cleaning and oiling might seem like small tasks, but they make all the difference in preserving your weapons beauty and functionality.

These steps can also be applied to any blade, whether it’s a European sword, a fantasy sword replica, or any similar blade made of high-carbon steel.

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